Combined gas and steam turbine plant using burner in gas turbine exhaust to heat steam



y 29, 1952 v. F. A. NORDSTROM ET AL COMBINED GAS AND STEAM TURBINE PLANTUSING BURNER IN GAS TURBINE EXHAUST TO HEAT STEAM Filed July 7, 1949generation proper. The heat generated on ordi and those-losses whicharise due to the steam Patented July 29, 1952 I 1 1 UNITED STATES PATENTOFFICE.

COMBINED GAS AND STEAM TURBINE Y PLANT USING BURNER IN GAS TUR- BINEEXHAUST T HEAT STEAM J Vilhelm Fredrik Andre Nordstriim, Stockholm, andDimitrij Andrejevitch Morosofl", Enskede, Sweden, assignors to De LavalSteam Turbine Company, Trenton, N. J., a corporation of New JerseyApplication July 7, 1949, serial No,163,488 In Sweden December 23, 19488 Claims. (Cl.6039.18 l 2 It is known that a lot of steam is consumed'onhigh thermal efficiency because the greatest part all ships for otherpurposes than for the power of the losses-the condenser loss-iseliminated,

nary cargo-steamers is mainly used for heating power engine beingincapable of completely utie rooms r the Staff, for use in the galley, 5li zing the available heat drop, are returned to the baths and so on.This consumpt on of heat is not steam in the form of friction or lostheat. so great that it calls for any particular consid- The abovestatements do not apply only to erat on. on old Car o-steamers t e Steameheat and power plants on ships but also to staquir 'd tor h at pu p s shas us y been tionary plants, e. g. for such industries as cellutakendirect from the steam boiler and pass lose and textile mills where greatamounts of through a reducing valve. On Diesel-driven ships power andsteam heat are required a SO-Ca ed d y boiler as a run, bee Even inacombined gas and steam power plant, install or Such p p S- However,there is e. g. of the type described in our co-pending U. S. a roup 0fSh p W e the C p of heat, application Serial No. 25,356, filed May 6,1948, in addition to that required for the power generaand comprising agas power engine unit and a tion proper, is oi such a value that itcalls for Steam Dowel-engine unit, the exhaust gases from e partieular 9ieni q p 9 the gas power unit bein utilized for the steam prises Whalmg5111135, k e a the generation in the steam power unit, steam may be whenthe cargo. of the ship consists Of'vlscous drawn on in the same manneras in pure steam oil, it must be heated to a certain temperature 315 (incertain cases to 400 1 so that on If in a combined gas and steam plantsome of can be pumped retdllywand qulckly' tt h thesteam is drawn on forheating purposes and cold season and m northern seas 1t 15 abso' it isstill desired to obtain the same power from lutely necessary to heat theoil in order that it the power plant, this cannot be attained unlessshall be posslble to pump It at In tank additional fuel is supplied tothe steam boiler sels are provided with Diesel engines for the'prosothat the additional amount of heat which is to plant. This results in ahigher gas temperature illustrative example it may be mentioned that atank vessel of about 16,000 deadweight tons geni t and the remammg part?the erally is provided with two Scotch steam boilers e sor 2 sur aces.of steam boner A capable of delivering about 10 tons of steam persteam;super i 'whlqh m gas and Steam hour, when necessary, for heatingthe cargo. plantlsi-plaqed m the near. the furnace During such heatingperiods it must, thus, be calppsslble m Order to obtttm as hlgh aculated with a consumption of fuel to the Diesel P e' m r as posslble atnormal dnve, engine in the form ofDiesel oilas Well as to the Yvlthoutdrawmg Steam would obtain Steam boiler plant in the form of fuel on toohigh a temperature at additional heating.

If instead of Diesel engines a steam plant is If the sup-erheater wereplaced in another zone used for the propulsion of the Ship the boiler 1ntheboiler where the gas temperature is lower, plant need only beincreased a little beyond What 40 {issued Superheeting temperature mightbe is necessary'for the power generation for the protamed a additionalheating, but a lower pe pulsion Such an arrangement must absolutelyheating temperature would be obtained at drive be cheaper and simplerthan'the installation or Without additional i resulting in areducspecial steam boilers for heating purposes. t of t e thermalemcieney 0f the P t As the steam pressure in the boilers generally {5The p e t invention avoids the cited difliis considerably higher thanthat corresponding to 011111165 y dividing e superheater into Separatethe steam temperature required for-heating purpart e Of Which, pp d W thSaturated poses, the steam is allowed'to work in one or more Steam 't bil is p ed in the exhaust expansion stages of the steam power enginesand conduit from the gas turbine to the furnace of its pressure isreduced to a value suitable for the 56' the steam boiler, and the otherone, supplied with bleeding for heating purposes, thus, at the samesteam from the first superheater part and delivtime some of the heatcontent of th steam for ering" it to the steam turbine, is placed in thethe power generation. steam boiler within a temperature zone in which,

The heat quantity taken out in this manne at normal drive Withoutadditional firing, the gas for the power generation then works with avery temperature is approximately the same as the steam temperatureafter the first superheater part. b

By dividing the superheater andplacing its respective :parts in thismanner the following advantages are obtained.

The first superheater part, which is dimensioned so as to give the steamthe desired superheated temperature at drive withoutuadditional firing,fulfills its purpose on such: occasion, and the other parts then remaininactive, the temperature difference between gases and steam which is acondition for the heattransmission to the superheater, being zero,

If it is now desired to draw off some-steam for heating purposes and atthe same time to maintain the power developed by the power plantunchanged, it is necessary to burn 'additionalfueljn the furnace of theboiler and at the same time to increase the quantity of the feed water.'.In this case the steam quantity passing through the superheaterbecomes greater than at drive *without drawing-off and-the. steamtemperature after the first superheater part becomes lower. :As 'at thesame time, due to the additional firing, the gas temperature/in theboiler rises, the other superheater part will have a temperaturedifference between gases and steam which results in heat transmission tothe steam in this part of th superheater.

Calculations .have shown that if the second superheater part isdimensioned in suchmanner that at amaximumv ofgsteam drawn-ofiior.heatin purposes a superheating temperature is obtained, which isapproximately as high .as at drive without draWrQfL'this temperature canbe attained also for all intermediate values of the drawn-off steam,which results in a high steam turbine efiiciency at all drive 7conditions.

The invention will be described hereinafter more in detail withreference to the accompanying drawing showing in more or lessdiagrammatic form a. suitable embodiment of apparatus for carrying theinvention into effect.

In the drawing the numeral I designates an air compressor which maybeprovided with an intercooler. The air compressed in the compressor isfirstpreheated in a regeneratorA by means of the waste gases to atemperature which may be controlled by a damper 5, and is then heated tothe desired admission temperature in a com-- bustion chamber 6. 'Fromthe gas turbine! which drives the compressor l and an electric generator8 normally delivering current to the auxiliary engines of the plant butalso serving as starting motor at the starting of the plant, the exhaustgases are led to a combustion chamber-S where they are reheated. Byadjusting a damper I I, the exhaust gases from the turbine 1 can be leddirect to the steam boiler I2past the gas turbine I0.

After having been reheated in the combustion chamber 9, the exhaustgases work in the :gas turbine I which viaa-gear l8 delivers power to apropeller, for example, 'then pass via the first superheater part tosteam boilers I 2 where they give off the greatest part of their heatcontent, and further 'pass through an economizer l4 and a regenerator 4before being discharged to waste through the smoke stack.

The generated Jsteam led from the steam collector of the boilers to thefirst superheater part 20, 'thenlpasses to the second superheater part13 and further to the steam turbine'aggregate l5 and, after expansion insaid aggregate, to a condenser i'l'from .which the condensate is raisedto a so-called hotwell 22 by means of a pump device 2|. A feed pump 23pumps the condensate from the hotwell 22 via the economizer 14 to thesteam boiler l2. In this embodiment an astern turbine is designated byI9, an

7 additional burner by 24 and steam taps for heating purposes by 25.

Under different operating conditions, which in somenas'es call foradditional fuel to be supplied to the boiler and in others do not, andwhich may call for different amounts of steam for .power and for heatingpurposes, it may be :desirable to bypass one or the other of the parts"of the-superheater or to connect them in parallel with respect to steamflow and to this end the plant may advantageously be equipped withsuitable conduits and valves for the purpose, as shown in Fig. 1. 'Bymeans of conduit 26 and valves 21 and 28, the part 20 of the superheatercan be bypassed. By means of conduit 29 and valves 30 and 3|, the partl3 can be by-passed. Also :by means ofbranch conduit-32 and valve 33 theparts can be connected in parallel, theby-pass conduit 26 being closed,by-pass conduit-29 being. open and va-lve3l closed. I

Weclaim: H .2

1. A powerplant comprising a gas power section including compressormeans, heating means and enginemeans for compressing,.-heating andexpanding-gaseous motive fluid comprising products of combustion; .asteam power'section-including boiler means having a furnaceand'superheating means for generating superheatedsteam and-engine-meansfor (expandin the same conduit means for conducting hot exhaust gasesfrom said gas power section to said b oiler means to generate steamtherein, fuelburning means in said furnace for selectively supplyingadditional heat to said boiler means, said superheating means beingdivided into "at least two parts, a first part being located in advanceof said fuel burning means to be traversedby the exhaust gases from saidgas power section, prior to delivery of the gases tothe-boiler means anda second part being located'to be traversed both by gases from said gaspower section and by gases genera-ted by said fuel burning means, andmeans for extracting steam from 'said steam :engine means after at leastpartial expansion thereof in the latter.

2. vA plant as defined in claim 1 including conduit means connectingsaid first and second parts of the superheating means for fiow of steamtherethrough in the order named.

3. A plant as defined in claim 2 including additional conduit and valvemeans for selectively connecting said superheater parts in parallel withrespect to steam flow.

4. A plant as 'definedin' claim 2 including additional conduit andvalve, means for selectively by-passing one or the other of saidsuperheater parts with respect to steam fiow.

-5. Aplant as defined in claim 2 in which said first superheater parthas sufiicient area to alone superheat the steamto desired finaltemperature fromheatderived from the gases exhausted from the gas power.section.

6. A plant as defined in claim' 5 in which said second superheater partis located ina zone in said'boiler means in which the gas temperatureresulting from operation of the boiler means solely with exhaust gasesfrom the gas power section is approximately the same as "the steam.tem-'- perature of the steam discharged from said first superheaterpart.

5 7. A plant as defined in claim 5 in which said second superheater parthas sufficient area to superheat to desired final temperature theincreased steam supply generated by augmented feed water supply andoperation of said fuel bum- 5 ing means to furnish the maximum requiredamount of extraction steam.

8. A plant as defined in claim 1 in which the capacity of the gas powersection is sufficient to supply at least 50% of the maximum total heat10 1,991,114

required by said steam power section.

VILHEIM FREDRIK ANDRE NORDSTRM. DIMITRIJ ANDREJEV'ITCH MOROSOFF.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,948,538 Noack Feb. 27, 19341,978,837 Forsling Oct. 30, 1934 Noack Feb. 12, 1935 2,012,967Meininghaus Sept. 3, 1935

